2002 Ultimate StreetCar Challenge: Emissions

Just as in real life, one car emitted far more pollutants than all the others put together. Our emissions test was basic, but still provided insight into the various cars' states of tune. Eurosport Accessories loaned us its Sun analog gas analyzer for the test, allowing us to measure hydrocarbon and carbon monoxide emissions.

Most cars were fairly clean. The Ferrari's readings were barely above ambient conditions inside the dyno room on either scale. The 510, with its ported rotary, pegged the HC meter immediately. We changed to the high scale, and it pegged again. The rest fell in between, most of them surprisingly closer to the Ferrari than the 510. The Mustang was dirty at idle, but cleaned right up at 2500 rpm. The Skyline opted out of this test, receiving a zero score.

The MR2 was interesting. Using a stock ECU and big injectors, it basically relied on oxygen sensor feedback and a big intercooler to run without blowing up. In the past, we've featured cars like that, whose owners say they seem to run well enough. Injector and engine management people say they don't run well enough. We got to see the feedback in action. After any change in throttle opening, emissions would jump dramatically, settling back to acceptable levels within a couple seconds. We recorded the steady-state readings because they were measurable and repeatable.

They reflect what would happen while driving down the freeway. The dirty emissions, however, reflect what happens while accelerating through the gears. It takes real management to be really clean.